Dehydrating process



` De.31, 1940. F Y HUK 2,227,246

v DEHYDRATING PROCESS Filed Jan. 17, 1938 l f- (-Z-Y Wea/m en/ reagen/@f90/Oper INVENTOR.

ATTORNEY.

resented Dee. 3i, i940 y 2,227,246

UNITED STATES PATENT OFFICE DEHYDRATING PROCESS Few Yap chuck, sonFrancisco, Calif. Application January i7, 1938, Serial No. 185,420

15 Claims. (Cl. sisi-154)` This invention relates generally to processesfor tion of a further reagent like calcium lactate is the dehydration ordrying of fresh leafy vegetable desirable in order to afford a buffermedium tendmaterials, like alfalfa or spinach,l and to products ing toretain the final product in slightly acid conresulting from suchprocesses. dition. Addition of a preservative like benzoic In the pastthe drying of fresh vegetables like acid, is also desirable. Drying canbe carried out 5 alfalfa or spinach, has been subject to two prinbyconventional ways, but preferably involves cipal disadvantages. In therst place such macontinual agitation of the material in comminutedtel-19.15 when chopped r comminuted, are dif- Condition, While thematerial is being contacted cult to dry by ordinary methods; because thewith the drying gaa l0 chopped material tends to agglomerate together,Referring iirSt to the fiOW Sheet of Fig- 1'. l0

thus precluding emclent contact with the drying fresh leafy vegetablematerial, suchas alfalfa, is gas. The second and more seriousdisadvantage Shown being supplied to a suitable mechanical has been thatthe dehydrated product produced Chopper l0. Line ll indicatesintroduction of deteriorates rapidly with respect to carotinoid Smallamounts 0f treatment reagents into the l and vitamin content, bothduring and after chopper I0, to intermix with the alfalfa. These 15processing. Loss of carotene and vitamin content treatment reagents canconveniently be in the isaccompanied by a rapid loss of color, so thatfol'ln 0f a dry powdered miX- The material being within a comparativelyshort time the material discharged from the Chopper In is shown beingloses freshness and its original vitamin and carodelivered byeonveyorl2, to the drum dryer l3- tene content, particularly 1f exposed to theught, Further intermixture occurs in the conveyor l2, 20

It is an object of the present invention to and a Dart of the materialfrom this point Can provide a dehydration process which will facilibereturned to the chopper l0, to effect a final tate the mechanics ofremoving moisture from chopping, aSindieated byline |4 The drying gdethe material, and which will also result `in a sta- Supplied to thedryercan be heated carbon dioxbilized product, which will keep for longperiods ide, in order to minimize oxidation and to convert 25 of timewithout serious deterioration in caroany hydroxide Present (Such aSCalcium hydrox-A tinoid and vitamin content. ide) to carbonate.

It is a further object of the invention to pro- The process representedby Fig- 2 iS Similar to vide e process making possible a stabilized de-Fig. 1, except that two choppers are employedhydrated product of highvitamin and carotinoid Thus chopper I0 is shown delivering material to30 value, which will retain its green color for a relthe conveyor andmixer I2, which in turn delivers atively long period of time, and whichwhen the material to the second chopper l5, for fine stored will not besubject to mold formation or chopping. The powdered reagents can bepneulike spoilage. l matically blown into the material leaving chopperAnother object isto provide astable dehydrated l0, before this materialis introduced into the vegetable product which will retain itscarotinoid Second Chopper I6. and vitamin potency over long periods ofstorage Best results have been `secured by using a drir and which willafford a superior stock feed. powdered mix of compoundsy includingSloked Additional objects of the invention will appear lime, ealeililnChloride, Calcium Carbonate, tanni@ from the following description inwhich the preacid. Calcium lactate and benzoio acid- Suitable 40 ferreaembodiment of the invention has been set proportions for such reagentsare as follows:

forth in detail in conjunction with the accom- Pounds paging drawing'sleked lime moo erung to the drawing' Calcium chloride 50i) Figs. l and2 are flow sheets illustrating two Calcium carbonat m00 45 suitableprocedures for carrying `out the present Tamm acid wn process. Y

The present process is characterized by addi gfziouixatate o 5gg tion ofsmall amounts of .reagents like lime and calcium chloride, to the freshmaterial being About l2 pounds of theabove mix will suffice 50 treated,in order 'to neutralize plant acids, and for the treatment of oneton ofwet hay or alfalfa. to cause a. hardening of theplant fibre. It is alsoAs `previously mentioned the function of the preferable to introducesmall amounts of a relime is to react with and substantially neutralizeagent like tannic acid or a related tannin complant acid. 'Ihis is ofsignificance in connection pound, in order to inhibit enzymic activity.Addiwith the preservation of carotinoids, because 55 carotlnoids areunstable in acid, but'are comparatively stable and are preserved underslightly acid or substantially neutral condition. Further-V moretreatment with lime serves to harden the plant fibre, presumably becauseof the action of the hydroxide upon plant protein. In any event the limeexerts a. noticeable stiffening action upon leafy fibre, and this inturn tends to prevent agglomeration of the comminuted material, duringthe final drying operation. After treatment with lime, the materialreadily segregates itself in a drum dryer, so that there is no packingand no agglomeration, but instead there is present a mass of materialwhich readily falls apart into its component fragments, thusfacilitating intimate contact of the individual particles with thedrying gas.

Fair results have been secured by using slaked lime alone as a treatmentreagent, slightly less than that required to combine with plant acid. Insuch instances the excess lime can be largely, if not entirely convertedto calcium carbonate, in the final drying operation, by the use of hotcarbon dioxide as a drying gas. i Addition of other reagents isdesirable however, for reasons which will bepresently explained indetail. Use of a considerable amount of calcium carbonate in place of apart of the slaked lime, makes it possible to reduce the amount of limeemployed. Such use of calcium carbonate minimizes any unreacted lime tobe converted to calcium carbonate by the final drying operation. Calciumcarbonate is a mild neutralizing agent, which is not as active in thisrespect as slaked lime. By using both slaked lime and calcium carbonateplant acids can be rapidly neutralized,vwithout danger of over-limingwith resultant undesirable Valkalinity, such as might be injurious tocertain vitamin values, like flavins or v itamin G complexes. In theexample cited above the amount of slaked lime is considerably less thanthat required to completely neutralize plant acid, although the reagentmixture neutralizes to the desired extent. The calcium chloride contentassists in hardening plant bre, and its use also enables a reduction inthe `amount of lime without sacriilcing the desired hardening effect.

It isgenerally knownthat enzymic activity is destructive #to certainvitamin values. In dried alfalfa and like products enzymic activity iscatalized or activated by the presence of colloidal iron and manganeseand possibly other like metals or metallic compounds. The t/annic acidcontent specified above serves the `useful purpose of precipitatingcolloidal iron and manganese, andi-like substances present, -thusminimizing or disrupting enzymic action. Tannic acid also serves theuseful purpose of affording an anti-oxidant.` As an example of relatedtannins which can be em` ployed, reference can be made to pyrogallol.

It is desirable to employ the calcium lactate content in place ofcorresponding amounts of lime, because this salt serves as a bufferhaving an anti-enzymic'action. It tends to more definitely fix thehydrogen ion concentration of the material, whereby the pH value of thefinal material is only slightly acid, and in the order of from pH 6.5 to6.8. Some unreacted calcium lactate remains in the final material, toserve as a solid buffer as pointed out above. Presence of calciumlactate during processing also serves to prevent excessive action` ofthe lime, and minimizes possible'injury to carotene and vitamin G byvirtue of the strong alkalinity of the lime.

The benzoic acid content referred to above serves as a preservative andanti-fermenting agent. Thus the product is made more immune to possiblespoilage, even though it is freely subjected to the atmosphere oradverse climatic conditions during storage. In place of this particularsubstance I can make use of other preservatives like boric acid orsalicyclic acid.

The amount of the reagent mixture used can be adjusted somewhatdependent upon the type of vegetable material being dehydrated. Theamount which has given good results with ordinary alfalfa has beenindicated above. ness with which the material is comminuted will dependupon the type of product desired. In general with my process it ispossible to chop to a greater degree of fineness, than in priorprocesses, because of the facility with which the material can be dried.In preparing a stock feed I prefer to chop to a particle size ofone-quarter inch or less. Y

The dehydrated product produced by my process appears much greener incolor than products produced by other dehydrating processes. It has beenkept over periods of several months, without material deterioration incolor, carotene or vitamin content. I attribute the preservation ofcolor to the minimum rate of oxidation of color components both duringand after drying, and to some form of color stabilization taking placebecause of the reagents employed. This is in contrast with conventionaldried alfalfa, which when exposed to daylight; largely loses itscarotene content and green color in about five days. As will be evidentfrom the foregoing the nal product contains small amounts of residualsolid phase calcium carbonate and calcium lactate. together with smallamounts of tannic acid o1' related tannins and traces of benzoic acid orrelated benzoate compounds. All such compounds are homogeneouslydispensed throughout the dried material. The nal material has someresidual moisture, such as from 6 to 15%.

It is frequently desirable to subject the product produced as describedabove, to further treatment to inhibit oxidation and in general toextend the period over which the product can be stored without seriousdeterioration. This can be accomplished by adding small amounts ofa'neutral mineral oil, as for example by atomizing thin numeral oil intothe product, while the product is in suspension. The small amount of oilthus applied to the material serves as a sealing agent, thus protectingthe material against oxidation. Deoxidants like hydroquinone, and oilsoluble vitamin values like carotin, can be introduced into the oil, tofortify the vitamin content. Onehalf (1/2) to one (l) percent (byweight) of oil, will give good results.

I claim:

1. In a process fordehydrating freshleafy vegetable material, likealfalfa or spinach, comminuting the fresh vegetable material andsubstantially neutralizing plant acids contained in the same, and thenremoving moisture to form an uncooked dehydrated product.

2. In a process for drying fresh leafy vegetable material, like alfalfaor spinach, comminuting the fresh vegetable material and treating thesame to the action of a calcium compound, the calcium compound servingto substantially `neutralize plant acids and to harden the fibre, andthen removing moisture to form an uncooked dehydrated product while thematerial `is in a state of continual agitation.

The ne- 3. `*In* a process for dehydratingl `fresh leafy vegetablematerial, like alfalfa onspinach, comminuting the fresh vegetablematerial and treat` 4,1m a process for treating freshleafy` vege-` tablematerial, like alfalfa or spinach, comminuting the fresh vegetablematerial, `treating the same to the action of chemical reagents, thereagents including a neutralizing substance capable of substantiallyneutralizing plant acids and also capable of .hardening the plant fibre,l5" andfa tannin serving to precipitate colloidal lmetals, like iron andmanganese, whereby enzymic activity is minimized, and removing moistureto form a dehydrated product.

5.` In a process for treating fresh leafy vege- 20 table material, likealfalfa or spinach, comminutlng the fresh vegetable material, `treatingthe same to the action of chemical reagents, the reagents including aneutralizerserving to substantially neutralize plant acids. and a buffersalt 25 capable of maintaining the hydrogen ion concen'f 'tration in theorder of 6.5 to 6.8, and removing "moisture to form a dehydratedproduct. f

`6. `In a process for dehydrating fresh leafy vegetable material, likealfalfa or spinach, com, 3o minuting the fresh vegetable material,treating the same to the action of chemical reagents, the reagentsincluding a neutralizer. for substantially neutralizing plant acids andcalcium lactate as a `40"ing the same to thev action of chemicalreagents,

j the reagents including' calciumhydroxide and i 'calcium carbonate, andbeing capable of substantially neutralizing plant acids. and thenremoving moisture to form an uncooked dehydrated 45 product. y l

8. InV a process for dehydratlng `fresh leafy vegetable material, likealfalfa or spinach, comminuting the fresh vegetable material andtreatingthe same to the action of-'chemlcal reagents, 5o the reagentsincluding a calciuxnfcompound capable of substantially neutralizing:plant acids and also tannic acid, and then removing moisture to form adehydrated product. Y

, 9. In a process for the treatmentof fresh leafy 55 vegetable materiallike alfalfa or spinach, comanemie -l i minuting the freshL vegetablematerial, treating the same to the actionof chemical reagents. thereagents including calcium hydroxide, calcium carbonate, and tannicacid, the amount of calcium hydroxide and calcium carbonate beinginsufllcient to afford a substantial alkalinity after neutralizing plantacid, and removing moisture to form a dehydrated product.

10. In a process for the treatment of fresh leafy vegetable materiallike alfalfa or spinach, comminutingthe fresh vegetable material,treating the material with chemical reagents, the reagents includingamixture of calcium hydroxide. calcium chloride, calcium carbonate,tannic acid, and calcium lactate, and removing moisture to form adehydrated product.

l1. In a process for the treatment of fresh leafy vegetable material,like alfalfa or spinach, oomminu-ting the fresh vegetable material,treating the same to the action of chemical reagents, the

"reagents including calcium hydroxide, and

calcium lactate. and removing moisture to form a dehydrated product.

l 12. Ina process for drying fresh leafy vegetable material like alfalfaor spinach, comminutlng the freshvegetable material, treating the i sameto the action of chemical reagents, the re- 1 agents includinganeutralizer capable of substantially neutralizing plant acids, atannin, a buffer salt capable of maintaining a pH value in the order of6.5 tol 6.8, and benzoic acid as a preservative, and removing moistureto form a dehydrated product.

13. In a process for dehydrating fresh leafy vegetablematerialrlikealfalfa or spinach, comminuting the fresh vegetablematerial. treating' thel same to the action of a tannin and removingmoisture to form an uncooked dehydrated product.

14.In a process for the manufacture of dried vegetable material likealfalfa, comminuting the fresh vegetable material,` introducing aneutralizing reagent with the material to neutralize plant acids,removing moisture to form a dried uncooked material, and adding smallamounts of mineral oil to the material to seal and protect thecomminuted particles. f

15. In a process for the manufacture of dried vegetable material likealfalfa, oomminuting the fresh vegetable material. introducing` a tannininto the material, removing moisture to form a dried uncooked material,and adding small amounts of mineral oil to the material to seal andprotect the comminuted particles.

FAW YAPCHUCK.

